Cable system for bone securance

ABSTRACT

Surgical crimping pliers have operating handles and connected, opposed jaws. The jaws define opposed recesses for carrying and crimping a tubular crimp member, which is preferably of oval configuration for carrying a plurality of multistrand cable sections so that, upon crimping, the cable sections are secured together. A capstan is carried on one of the handles for winding a plurality of cable portions so that tension may be placed on both ends of a cable loop array wound about a bone structure, to provide a predetermined, quantitative tension. Then the cable sections within the crimp are secured together by collapse of the crimp. A multistrand cable is preferably used, which exhibits great advantage over single strand wire, and which carries surgical needles of differing type secured to each end thereof.

This is a division of application Ser. No. 08/201,614, filed Feb. 24,1994, now U.S. Pat. No. 5,536,270.

BACKGROUND OF THE INVENTION

This present invention is a surgical cable system for securance of thesternum following coronary bypass surgery, as well as for other desiredbone securance uses.

In Songer, et al. U.S. Pat. No. 5,116,340 a surgical securance apparatusis disclosed in which a loop of surgical cable may be formed withcrimping pliers having a capstan on one of the handles, for winding thesurgical cable to provide crimping under a desired and predeterminedlevel of tension. While this system is being successfully used invarious clinical applications, there are certain desired clinical usesof crimped surgical cables for which the system of the above-citedpatent is not optimum. Thus, by this invention, improvements areprovided in surgical cables and the handling thereof to facilitateadditional surgical procedures, above and beyond what was possible inthe prior art.

In the prior art, surgery in and adjacent to the heart generallyrequires the central opening of the sternum to provide the surgeon withaccess. After the operation, the sternum is closed, typically withmonofilament wire of about twenty gauge. Such wire is subject tobreakage. Additionally, monofilament wire can not be tightened to adegree that is often desirable since, as wires are tightened, the wireis stressed so that further tightening may fracture the wire. However,if the wire tension against the sternum is undesirably low, the sternumis not rigidly fixed. This results in more post-operative pain than inthe case with patients which have a rigidly fixed sternum due to bettersecurance.

For this and other reasons, the monofilament wire securance of thesternum in accordance with the prior art has disadvantages andshortcomings.

DESCRIPTION OF THE INVENTION

In this invention, crimping pliers are provided which comprise a pair ofoperating handles in connected, opposed jaws. The jaws define opposedrecesses for carrying and crimping a tubular crimp member by manualpressure on the operating handles. A capstan is carried on one of thehandles for winding a pair of cable portions which respectively passthrough a tubular crimp member carried in the jaws. The capstan alsocomprises a rotating handle for effecting the winding of the pair ofcable portions.

The crimping pliers of this invention may have a capstan which comprisesa pair of separate, rotatable drums for respectively receiving woundcable portions of the cable pair, the drums being each simultaneouslyrotated by the handle.

It is also preferred for the jaws of the crimping pliers of thisinvention to carry at least one laterally mounted wheel member,positioned to peripherally receive a portion of a cable extendinglaterally from the crimp member in the jaws, to cause the portion of thecable to peripherally bend around the wheel to extend longitudinallyalong the pliers, to engage the capstan. Thus, this approximately rightangle bend of the cable makes possible the effective tightening of thecable without frictional binding or imposing a sharp angle on the cable,as the cable passes through a crimp member which is transverselypositioned in an elongated chamber of the crimping pliers jaws.

Preferably, a pair of such wheel members are provided, each carried onan opposite side of the jaws, and each wheel member respectively soengaging one of the pair of cable portions.

Typically, the cable portions may be sections of the same cable, so thatboth ends of the same cable may be tensioned by the crimping pliers ofthis invention, to provide desired tension in a surgical cable windingsupporting bones of the patient. For example, cable windings where thesternum is reclosed is illustrated in one of the drawings below. Then,crimping of the crimp member about the two cable sections of each cablewinding can secure a central portion of the cable together into a closedloop winding, followed by cutting away both cable end portions which areoutside of the crimp.

Opposed recesses defined in the pliers jaws preferably together definethe elongated chamber of the jaws when the jaws are closed, whichchamber extends in a direction normal to the axis of the pliers and tothe direction of the jaw opening and closing in its longest chamberdimension.

Preferably, the crimp which is placed into the jaws of the pliers andcollapsed therein is tubular. The crimp is preferably of ovalcross-section, having a major and a minor oval axis. The major axis ofthe cross-section is preferably positioned in the direction of jawopening and closing. Thus, when the crimp contains two separate lengthsof cable in side-by-side relation, as facilitated by the oval section,collapsing of the crimp causes the crimp at first to typically assume across-section which is more circular, followed by collapse into aconfiguration where the cables are firmly retained together.

It is also preferred for the above crimp to define an outwardlyprojecting flange about each end thereof. The respective flanges arepreferably frustoconical in shape, having a side angle to the tubularcrimp longitudinal axis of about thirty to sixty degrees.

The surgical cable of this invention is preferably of multistrand type,having about 30 to 100 wound strands. Prior to emplacement in a patient,it may define a pair of opposed ends, each cable end being permanentlysecured to a surgical needle. Preferably, each of the surgical needlesare of different types so that the cable can be easily implanted throughdiffering types of tissue, with one needle being more effective for sometypes of implantation of the cable and the other needle being effectivefor other types. Specifically, one of the surgical needles may define agenerally conical end terminating in a point, while the other of thesurgical needles defines a point and a lateral cutting edge.

DESCRIPTION OF THE DRAWINGS

Referring to the drawings,

FIG. 1 is a plan view of surgical pliers made in accordance with thisinvention;

FIG. 2 is an elevational view of the surgical pliers of FIG. 1;

FIG. 3 is a perspective view showing the surgical pliers of FIGS. 1 and2 in use with a torque wrench, securing and tensioning a cable which iswound around the sternum of a patient to reclose the sternum aftersurgery;

FIG. 4 is an enlarged, fragmentary, elevational view of the jaws of thepliers of FIG. 3 and the crimp of this invention, with the cablespassing through the crimp being shown in section;

FIG. 5. is a fragmentary, sectional view taken along A--A of FIG. 4;

FIG. 6 is a fragmentary perspective view, showing the loading of a crimpinto the opposed recesses of the jaws of the pliers of the previousfigures;

FIG. 7 is a plan view of a multistrand, surgical cable in accordancewith this invention, usable with the pliers and surgical procedure shownin the previous drawings; and

FIG. 8 is a plan view of the sternum of a patient, showing one way thatsurgical cables may be implanted to close the sternum in accordance withthis invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Referring to FIGS. 1 and 2, ratchet type crimping pliers 10 are shown,comprising a pair of operating handles 12, 14, and connected, opposedcrimping jaws 16, 18. The mechanism of crimping pliers 10 may besubstantially that of the prior art except as otherwise indicatedherein, where the rotating of handles 12, 14 about pivot 20 causespivoting of jaws 16, 18 about respective pairs of pivots 22, 24. Jaws 16and 18 rotate about pivot axes that are perpendicular to a closure planeof the jaws. Pivots 22 extend through a pair of metal straps 26 for thepivoting support of jaws 16, 18. Pin 27 is provided for load equalizingbetween straps 26, and fits loosely between jaws 16, 18.

Also, each of metal straps 26 carry a laterally mounted wheel 28, eachof which has a periphery positioned in lateral or transverse manner toreceive a cable portion passing through transversely elongated chamber30 which is defined by opposed recesses in the respective jaws 16, 18,being more particularly illustrated in FIGS. 3-5. In FIG. 4, cableportions 32, 34 are shown to be positioned within elongated chamber 30as defined by recesses 30a and 30b. Cable portions 32, 34 are surroundedby tubular metal crimp 36, which is retained within elongated chamber30.

As shown, tubular metal crimp may preferably have an oval cross sectionboth in its outer periphery and its bore 38, with the recesses 30a, 30bbeing proportioned to receive crimp 36 with its oval cross section majoraxis extending in the direction of jaw opening and closing as shown inFIG. 4. Thus, upon closing of the jaws (the jaws of FIG. 4 being in anincompletely closed position) crimp 36 is collapsed first toward a bore38 of more circular configuration, followed by a collapsed configurationthat firmly retains cable portions 32, 34 together in bound relation.

Also, tubular crimp 36 is shown to have an outwardly projecting flange40 on each end thereof, which may be a flaring end at an angle of about45° to the major access of tubular crimp 36, or any other desiredflange. One main purpose of each flange 40 is to facilitate introductionof cables in each direction through the crimp. Also, flanges 40 helpretain crimp 36 in the position within elongated chamber 30 definedbetween jaws 16, 18, so that the crimp does not easily fall out of itsposition as cable portions are being threaded through it, prior to thecrimping process exerted on crimp 36 by the pliers 10.

Cable portions 32, 34 comprise separate sections of typically a singlecable 42, which has end sections 32a, 34a, each of which extend fromtheir respective cable portions 32, 34 within crimp 36 laterallyoutwardly about a respective wheel 28 and then rearwardly along thepliers handle 12 to a capstan member 44 (FIG. 2). Capstan member 44comprises a shaft which carries a pair of rotary drums 46 on oppositesides of handle 12, with shaft 45 extending completely through handle12. Shaft 48 also extends through the end of handle 12 as shown to serveas a single, rotating handle for controlling the winding of drums 46through typically a self-locking worm gear arrangement with shaft 45.Either shaft 45 or shaft 48 may comprise the worm gear, with the othershaft carrying an appropriate rotary gear for engaging with the worm, inthe manner similar to that specifically illustrated in Songer U.S. Pat.No. 5,116,340, the disclosures of which are incorporated by referenceherein.

As shown in FIG. 3, a torque wrench 50 may be provided to engage shaft48, and rotated to cause corresponding rotation of shaft 45 and bothdrums 46. Thus the respective cable ends 32a, 34a of cable 42 may besimultaneously tightened.

In FIG. 3, cable 42 is shown to be wrapped about the sternum 52 of apatient which has been split for surgery within the rib cage. Then,cable 42 is wrapped in a desired, surgical manner about the sternum.Both end portions 32a, 34a are tightened in the manner illustrated byrotation of the torque wrench to wrap the ends of cable 42 about bothdrums 46 in simultaneous manner. Thus, the wrapping of a central cableportion about the sternum 52 is accomplished until a desired tightnessis reached, which may be controlled by an appropriate setting on thetorque wrench 50. Then, pliers 10 may be activated to crush crimp 36, tohold cable winding 54 in a permanent, closed position about the sternum.Following this, the end portions 32a, 34a of the cable outside of crimp36 may be cut and removed, resulting in a finished, surgical cable loopwindings of a type similar to that shown in FIG. 8.

In FIG. 8, a closure of the sternum is seen, using a pair of cablewindings which may be simultaneously applied with a pair of pliers 10,or sequentially applied with the same set of pliers. The cutting of thecable sections outside of crimp 36 has been accomplished, leaving eachcable portion 42 secured together in a loop form which is convolutedabout the sternum 52 in a manner deemed best by the surgeon.

FIG. 6 shows how the crimp 36 of this invention can be placed into theelongated chamber defined between the recesses 30a, 30b in therespective jaws. The view of FIG. 6 is greatly magnified. Crimp passer58 comprises a handle which defines at one end a small projection 60which is at a 90° angle to the rest of the crimp passer 58. Projection60, in turn, fits into the oval bore 38 of crimp 36, to permit the crimpto be placed into one of the recesses 30b with its long oval axispointing in the direction of jaw closing. Then, crimp passer 58 may bewithdrawn, and the end flanges 40 of the crimp assist holding the crimpin position until the jaws are closed.

Pliers 10 may have a conventional ratchet assembly 62, which preventsopening of the pliers until the crimp is completely closed. However, aconventional release lever 64 is provided for release of the ratchet.

FIG. 7 shows the ends of cable 42, upon each of which is secured ashort, wire leader section 66 to which is secured a surgical needle 68,70. Needle 68 may define a conical, pointed tip 72 as is oneconventional design, while needle 70 may define a pointed tip 74 havinga cutting edge, as another conventional design. Thus, the same cable maycarry two different surgical needles to facilitate the emplacement ofthe cable under a wider variety of situations than is available forconventional application of wire or cable windings to bones.

Also, cable 42 may have a long, multistrand portion 42a, being a woundarray of preferably about 75 strands. For example, the cableconfiguration may comprise eight seven-strand, wound bundles which are,in turn, wrapped about a single, central bundle of 19 wound strands. Thestrands may be made for example of 316L ASTM F-138 Stainless Steel ortitanium 6A 4V ASTM F-136 alloy. Such a cable configuration is veryflexible and strong. The cable is also swaged for increased smoothness.Because of the two separate end needles, the cable can be driven by oneneedle through the bone, or it may be passed around the sternum as thesurgeon chooses by the other needle, or both. The presence of singlestrand leader wire 66 on each end facilitates the passage of the cablethrough crimp 36, typically after cutting away the needles.

Through the use of the multistrand cable of this invention, such a cablehas very good fatigue resistance and static strength, which makes itless resistance to breakage, comprising a significant improvement overcorresponding monofilament wire. Also, monofilament wire cannot betightened to the extent that cables can in the system of this invention.Often, wires break under conditions where the cable of this inventiondoes not.

Also, the cable system of this invention can be tightened to a knowntension through the use of a torque wrench, for example. This tension isthus reproducible, and can be adjusted to any desired clinicalsituation. Since the sternum can be more rigidly fixed, this contributesto less failure and less postoperative pain.

Also, the cable of this invention is very flexible, which makes itsinsertion much easier as it is wound around the sternum or other bones.This also facilitates the ease of removal of the cable if that becomesnecessary. Likewise, fewer cables may be required for securing thesternum in view of the increased strength of the cables overmonofilament wires, to speed up closure of the sternum.

Additionally, a cable in accordance with this invention, being stronger,can have less diameter than the wire of corresponding strength, whichdecreases the irritation which is common with wires. Likewise, there areno sharp ends in the implanted cable. Even if a break or failure occurs,the soft cable end is much safer than a broken wire end in terms of therisk of puncturing a blood vessel.

The above has been offered for illustrative purposes only, and is notintended to limit the scope of the invention of this application, whichis as defined in the claims below.

That which is claimed is:
 1. A method of securing a bone structure in apatient, which comprises:winding a cable having two end portions aboutsaid bone structure; passing said cable at least twice through a tubularcrimp to form a central portion of said cable into a loopedconfiguration; placing said tubular crimp into the jaws of crimpingpliers, in a position so that the cables extending from the crimp aretransverse to the closure plane of the jaws and passing the two endportions of said cable rearwardly from said jaws and crimp to a windingcapstan carried on said pliers; winding both cable end portions aboutsaid capstan to place said cable under a predetermined amount of tensionexerted from both ends of said cable; crushing said tubular crimp withsaid crimping plier jaws to secure said central portion of the cable insaid looped configuration into a permanently formed configuration underthe predetermined amount of tension; and cutting said cable end portionsaway adjacent said crimp.
 2. The method of claim 1 in which said cableis a multistrand cable.
 3. The method of claim 1 in which each of saidcable end portions extends transversely outwardly from said pliers andthen around a wheel member in an arc to then extend rearwardly of saidpliers into engagement with said winding capstan.
 4. The method of claim3 in which said crimp has a bore of oval cross section prior to beingcrushed by the crimping pliers, said crimp being mounted in the crimpingpliers with the major axis of said oval cross section being in thedirection of opening and closing of the crimping jaws.
 5. The method ofclaim 4 in which said cable is wound around said bone structure throughthe use of a pair of needles secured to opposed ends of said cable, eachneedle being of a different design from the other needle.
 6. The methodof claim 5 in which said cable defines a central portion between saidneedles comprising from 30 to 100 separate strands wound together. 7.The method of claim 1 in which said tubular crimp defines flanges oneach end, and defines a bore extending entirely through said crimphaving an oval cross section.
 8. A method of securing a bone structurein a patient, which comprises:winding a multistrand cable having two endportions about said bone structure; passing said cable at least twicethrough a tubular crimp to form a central portion of said cable into alooped configuration; placing said tubular crimp into the jaws ofcrimping pliers in a transverse position to the pliers, and passing thetwo end portions of said cable rearwardly from said jaws and crimp to awinding capstan carried on said pliers in which each of said cable endportions extend transversely outwardly from said pliers and then arounda wheel member in an arc to then extend rearwardly of said pliers intoengagement with said winding capstan; winding said cable end portionsabout said capstan to place said cable under a predetermined amount oftension; crushing said tubular crimp with said crimping plier jaws tosecure said central portion of the cable in said looped configurationinto a permanently formed configuration under the predetermined amountof tension; and cutting said cable end portions away adjacent saidcrimp.
 9. The method of claim 8 in which said crimp has a bore of ovalcross section prior to being crushed by the crimping pliers, said crimpbeing mounted in the crimping pliers with the major axis of said ovalcross section being in the direction of opening and closing of thecrimping jaws.
 10. The method of claim 9 in which said cable defines acentral portion comprising from 30 to 100 separate strands woundtogether.
 11. The method of claim 9 in which said cable is wound aroundsaid bone structure through the use of a needle attached to one end ofsaid cable.
 12. The method of claim 11 in which said cable is woundaround said bone structure through the use of a pair of needles securedto opposed ends of said cable, each needle being of a different designfrom the other needle.
 13. The method of claim 9 in which said tubularcrimp defines outwardly projecting flanges on each end, and defines abore extending entirely through said crimp having an oval cross section.